Activating a Nintendo eShop key is really easy, just follow these steps:
1/ Choose “Nintendo eShop” on the HOME Menu to run the Nintendo eShop.
2/ Select the account you intend to use.
3/ Pick “Enter Code” on the left side of the screen.
4/ Put the 16-character download code in.
Note that any letters or symbols not used with prepaid codes (i.e. O, I, Z, commas, hyphens, etc.) will not be available the on-screen keyboard
5/ Click“Send” to confirm. The product will begin downloading once the code is confirmed.
The product icon will appear on the HOME menu, with a download status bar. The status bar will disappear once the product download process is terminated.
The key is not working
If you have activated the key according to the guide but the code appears not to work, please check what type of error message you receive and depending on it follow the appropriate instructions: